Fifth-generation fighters, aircrew and support personnel from the 525th Fighter Squadron at Joint Base Elmendorf-Richardson, Alaska, arrived this week at Kadena Air Base, Japan, as the new theater security package, a term describing forward-deployed aircraft units that conduct missions to reassure partner and ally forces and maintain security and stability across a region.

The number of fighters that deployed was not disclosed.

"Pacific Air Forces TSP deployments to the Indo-Pacific region signify a continued commitment to regional stability and security and have served as a routine and integral part of U.S. Indo-Pacific Command's force posture since March 2004," Kadena's 18th Wing said in a release Thursday.

In December, a massive force totaling 230 aircraft participated in U.S.-led drills dubbed Vigilant Ace 18 with South Korean allies at Osan Air Base to focus on "interoperability, security and combat airpower," officials said at the time.

In 2016, F-22s alongside U.S. F-16 Fighting Falcons deployed to Yokota Air Base weeks after North Korea claimed it had conducted an underground nuclear hydrogen test. They were last at Kadena in 2014, the 18th Wing said.

The F-22s will align under the newly renamed U.S. Indo-Pacific Command while in the region. Defense Secretary Jim Mattis announced Wednesday that the U.S. military's largest command would change its name from U.S. Pacific Command to U.S. Indo-Pacific Command.

"Our 2018 National Defense Strategy is the first of its kind in a decade, and it acknowledges ... America's resolve and lasting commitment to the Indo-Pacific," Mattis said during a change-of-command ceremony at Joint Base Pearl Harbor-Hickam in Hawaii.

"America continues to invest vigorously in Indo-Pacific stability, bolstering the free and open rules-based international order that has enabled this region to grow and to thrive for over 70 years," he said.